Some residents and businesses within Connecticut's 860 area code will have an additional area code to become familiar with beginning this summer. The state Public Utilities Regulatory Authority (PURA) has announced that because of continuing local demand for telephone numbers, remaining unassigned telephone numbers in the 860 area code are expected to be exhausted by the end of this year.

To meet the continuing demand, the PURA approved a new area code, 959, to be assigned as an overlay to the 860 region. An overlay is the addition of an area code to the same geographic region as an existing area code. An overlay does not require customers to change their existing area code, personal telephone numbers, or the manner in which they dial local calls.

Connecticut is far from alone in the introduction of new area codes across the country, and it's not the first time for an area code overlay in the state.

Kentucky residents in the 270 area code saw the introduction of an overlay area code this week, as the 364 area code was introduced for some new customers. Indiana introduced 10-digit dialing last week to prepare for the introduction of an overlay area code this fall.

According to the North American Numbering Plan Administration, which handles the allocation of additional area codes nationwide, sixty percent of the U.S. state regulatory commissions – a total of thirty - have ordered overlays as the method of area code relief. Throughout 2014, 25 states will have overlays in place with five more states in various stages of implementation of their overlays. Three states (Indiana, South Carolina and Tennessee) t ordered their first overlay late in 2013, while California, the most populous state in the U.S., recently approved what will be their sixth overlay – the 415/628 combination coming to San Francisco.

Current plans call for the new 959 area code in Connecticut to go into effect August 30, 2014. After that date, customers requesting new service, an additional line, or in some cases, moving their service may be assigned a number in the new 959 area code. According to NANPA, area code 203, in the southwestern portion of Connecticut, has had an overlay of area code 475 available since December 12, 2009. The first 475 phone numbers have been issued within the past year, according to PURA officials.

In Nebraska, however, overlay day is said to be four years away. Published reports indicate that demand for new phone numbers has slowed as fewer people become first-time cell phone customers.

For most customers, the new 959 area code should have minimal impact:

existing telephone numbers, including current area code, will not change;

customers will continue to dial area code + telephone number for local calls, and 1 + area code + telephone number for long distance calls;

local calling areas will remain the same;

prices for calls and coverage areas will not change due to the overlay;

customers will still dial services such as 911 (211, 411, 811, etc.) with just three digits.

The North American Numbering Plan Administratin (NANPA) is an integrated telephone numbering plan serving 20 North American countries that share its resources. These countries include the United States and its territories, Canada, Bermuda, Anguilla, Antigua & Barbuda, the Bahamas, Barbados, the British Virgin Islands, the Cayman Islands, Dominica, the Dominican Republic, Grenada, Jamaica, Montserrat, Sint Maarten, St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines, Trinidad and Tobago, and Turks & Caicos.

The Atlantic reported last month that for a brief period in the 1990s, Lockheed Martin oversaw the administration of area codes; after Lockheed got involved with telecom concerns, however, the FCC decided that it needed a neutral and non-governmental body to administer the nation's numbers. Lockheed's numbering division divested itself and became Neustar, which remains under contract with the FCC, according to the magazine.

Local Connecticut customers should contact their respective carriers with questions about the new 959 area code, and are advised that they can check PURA's website (www.ct.gov/pura) for updates.